Induction of lactation: an economic study of tool for dairy heifers with successive reproductive failures

The aim of this study was to evaluate the economic viability of the use of a lactation induction protocol in Holstein heifers. Were collected data of nutritional, reproductive and sanitary management pre and post-lactation period from 30 induction heifers (IG) and 30 pregnant heifers (CG). All animals were inseminated around 14 months of age and started lactation at 23±4 months. The animals of IG were heifers do not pregnant after two inseminations and natural service e were induced to lactation according to protocol: from the 1st to the 8th day, 30 mg of estradiol benzoate were administered daily, together with 300 mg of progesterone. From the 9th until the 14th, animals only received daily doses of 20 mg estradiol benzoate. On 16th day, 0.56 mg of sodium cloprostenol was administered and injections of 40 mg of dexamethasone sodium phosphate were administered daily from the 19th to the 21st day. On the 1st, 8th, 15th and 22nd day, the animals received a dose of sometribove zinc. The animals of CG were managed according to the farm routine. The costs of the CG during pre and post lactation (nutrition, sanitary, reproduction management) e were higher than the IG, however, when evaluating the economic viability due to lower milk production, the induced group did not leave profit in the first year of use. When comparing the lactation induction with the sale of animals that did not conceive and purchase of animals for replacement, this last scenario showed itself as a better alternative. RESUMO: O objetivo deste estudo foi avaliar a viabilidade econômica do uso de um protocolo de indução a lactação em novilhas da raça Holandês. Foram coletados dados econômicos do manejo nutricional, reprodutivo e sanitário pré e pós lactação de 30 novilhas induzidas à lactação (IG) e 30 novilhas prenhes (CG). Todos os animais foram inseminados em torno de 14 meses de idade e iniciaram a lactação com aproximadamente 23±4 meses. Os animais do IG foram novilhas que não conceberam após duas inseminações e monta natural, e foram induzidas à lactação com o protocolo: do 1° ao 8° dia receberam aplicação de 30 mg de benzoato de estradiol juntamente com 300 mg de progesterona. A partir do 9° dia até o 14° receberam 20 mg de benzoato de estradiol. No dia 16 ocorreu uma aplicação de 0.56 mg cloprostenol sódico e nos dias 19 ao 21, de 40 mg de dexametasona. Nos dias 1, 8, 15, e 22, os animais receberam 500 mg somatotropina recombinante bovina. Os animais do CG foram manejados conforme a r